Magnetic recorder



mz3 o 4 R. GRAY ETAL MAdINETIc RECORDER A iii/'l' Nov. 4, 1952 FiledAug. 24,1946

Nov. 4, 1952 R. GRAY ET AL MAGNETIC RECORDER 4 sheets-sheet 2 Filed Aug.24, 1946 Nov. 4, 1952 R. GRAY ETAL MAGNETIC RECORDER Filed Aug. 24, 19464 Sheets-Sheet 3 /NVf/VroRS ROBERT GPAY No'v. 4, 1952 R. GRAY Erm.

MAGNETIC RECORDER Filed Aug. 24, 1946 4 Sheets-Sheet 4 Patented Nov. 4,1952 ltown, Mass., assignors to Raytheon Manufacturing Company, Newton,Mass., a .corporation of Delawarev `Ap'p'licaoion August 24, 1946,serial No. 692,890

sxclaims. (c1. .17a-100.2)

This inventionrelates 'to combination 'magnetic 'recording :and'reproducing devices and lmore particularly to portable id'evices'ofthis cla/ss..

Here'tofore, ,in the design ote'lectromagnetic recording, attempts' havebeen made toward reducing the bulk and weight of 'such devices. Theseattemptshavev 'been directed toward producing 'a unit of the size of atable model radio 'receiver and one `in 'which the use of .an ade-,quate power supply lwas necessary to drivev .the means used `for,urging 'the recording medium `along ia predetermined path.

However, .such jprior `types of magnetic recording and reproducingdevices donot `provide the .size and mobility' desired .in certainifieldsyof nendeavor",. For example, Irecording equipment ofthe classdescribed vfor usein some ields'mus't "be portable, `extremely compact,kandhave a power supply which does, not .require connection to vlanoutside usource of energy. Furthermore, v,the 'facility with which "therecording .medium can be hand'led 'is very impor'tant. "It is desirable"to `remove .'thefrecorded medium `without disturbing the 4'equipmentitself. Therefore, the present invention is directed 'toward providing adevice of thevv class described 'incorporating the fabove-mentionedfeatures and many others.

.Itjis an object o the .present invention to provide, in a deviceofthevtype Aabove described, A.a `complete magnetic recording and,reproducing unit.

` Another Objectis to providea .complte device of 'the type .describedwhich caribe .car-riedin the .manner roten .average size ,'folding .type'camera and bev approximately `-the ,same size.

4A l'iurther object .is to provide .a cartridge conf 4.taining therecording medium ywhich .can be finserted in or removed Afrom the devicewith .'facility. l

A still further :object is .to provide `a cartridge containing .therecording mediumand an electro- V,Irlagnetic recording yhead whereinrthe .recording Lmedium `:is prepositioned with .respect rito .said.head .and.-immediately .ready ,for luse.

Yetfanctherfobjectiis to :provide novekmeans for -:reelingfarid.unreeling the `recordingmedium l'controlling the means for `urging therecording 'medium along a predetermined path and the direction in whichsaid medium moves.

The novel features which it is believed characterize the presentinvention are set forth with particularity in the appended claims. The`in- `vention itself, however, both as to organization 'and manner ofconstruction, together with further objects and advantages thereof, maybest be understood lby "reference -to the following description, takenin connection with the accompanying drawings, vin which:

Fig. 1 -is a view of 4one embodiment of the vpresent invention lookingdown into the case of the device with the cover removed;

Fig. l2 is -a view'of the front of the device illus'- itrating thecontrols for same;

. Fig. `3 vis a fragmentary View of the side villus-- trating Yarecording time indicator and a portion `of the case cover;

Fig. 4 illustratesa 'longitudinal -view, in crosssectiOn, Vof themechanism for driving the #reels supporting `the 4recording medium,along line 4--4 Yof Fig. l;v

Fig. 5 is a partial transverse View ofthe reeldriving mechanism takenonline -55 vof Fig. 4;

Fig. 6 presents an unassembled view, in crossfsection, of the reels,their associated driving wheels, and the rod Supporting the `entire as-`sem-bly;

Fig. `l is VAa perspective view of the cartridge containing theelectromagnetic head and medium and the 'means for maintaining the reelsub? -stantially immovable when removed from `the device;

Fig. 8 illustrates Aa fragmentary View of the oscillating mechanism andthe pronged member which Aengages said mechanism;

Fig. 9 yrepresents-a view, in cross-section ofethe cartridge withrespect to the oscillating andfdriv- "ing mechanism, along "line 9-9 ofFig :1

Fig. -lcpresents aperspectiveviewfof the readfily demountable magneticerasing means, the dotted Aportion showing how it is removed;

fFig. 111 illustrates, vin perspective, -a novel switch-ingyarrangement, Lfor simu1taneousln-y con,- vtrolling'the currentto thedriving means-and the direction'of Ymovement of the recording-medium;

'.Fig. 12 `vis `a ldetailed `illustration -of lthe Icam Varrangementfory actuating the "current-controlling means depicted in Fig. '-1'1;and

Fig. -13is'a f ragmentary yiewof the recording "time mechanism. j v 1 i.l

`-Referrng 11n-ore particularly @t0 Fis- "1. the te.- `1ected`embodiment ofthe present invention com- 3 prises a case lu, preferablyconstructed of aluminum or equally light-weight metal, which houses theentire magnetic recording and reproducing means.

A fractional horsepower constant speed electric motor energized by arechargeable storage battery I2, of diminutive size, -is the drivingmeans for this unit. The control of current to said motor is through aswitch |3 connected to a pair of conductors 4, one of which goesto oneterminal of the battery I2 and the other to the motor II; the remainingconnection from the battery I2 to the motor is via the case Il). Theswitch I3 comprises a pair of contact members |3A and |3B, supported ina block member |81, Fig. 11. The switch I3 is controlled by manipulationof a knob |5 through the agency,v

of a pair of gears I3, a shaft I1 and a cam, illustrated in Fig. l1 ascam |85, attached to said shaft. The aforementioned control arrangement.is illustrated in greater detail in Figs. 1 0 and l1 Vand will bediscussed more thoroughly hereafter in connection with saidillustrations.

Connected to a shaft |8 of the motor II is a driving gear (not shown)which engages and drives an appreciably larger gear I9. The gear 4I9isheld in engagement with the'motor-driven gear (not shown) by a pair oflink members 20 and 2| fastened to the shafts I8 and 22. The ratio ofsaid last-named gears is such as to reduce they speed of a frictionaldriving Wheel 23 to a value sufficient to impart a proper rate of speedvto a driven wheel 24. The wheel 23 is covered with a resilientmaterial, preferably rubber, and the driven wheel 24 is preferablyfabricated of aluminum or similarly light-weight metal. The proper rateof speed mentioned above is a rate suitable for intelligible recording.The wheel ,24, through the agency of ashaft 25, to which it is attached,drives a plurality of clutch mem- .bers' 26 and 26A. They in turn engagea pair of driving Wheels 21 and 28, and said pair of wheels frictionallyengage and drive a pair of reel-driving Wheels 29 and 30 connected to apair ofv reels 3| and 32, in a manner to be de- 45 scribed below.Tension on the wheels 21 and `2,8 is maintainedl by a spring member 24Aattached to the link 2|, the other end of the spring being anchored tothe bottom of the case I0. The `spring 24A urges the wheel 23 toward the@front of the case I8 and against the Wheel 24. The wheels 21 and 28,having a common support- .ing shaft 25, are consequently urgedin firm.ducing head 35.`

A plurality` of periphically grooved guide wheels .34A, in thisparticular embodiment a pairv of `such Wheels, y is used to guide therecording medium 33 along the path above mentioned The wheels 34A haveball bearings to reduce the friction between said guide wheels and therecording medium to a minimum. Furthermore, the reduction of frictionbetween said last-namedy components also reduces the torque imposed on4the .fractional horsepower motor used in this particular embodiment.

Details of the reel-driving .mechanism are shown in Fig. 4 and of thereels 30 .and 3| in Fig. 5. These items will be discussed at length inconnection with said last-'named figures.

The head 35 is supported on a member '38, said member being slidablycarried by a pair of parallel rods 31 attached to the walls of a framemember 38. The frame member 38 supports a shaft, illustrated in Fig. 6as shaft |41, which in turn supports the wheels 29 and 3B and the reels3| and 32. All of the aforementioned components contained within saidframe member 38 will be referred to hereinafter as a cartridge. Thecomplete assembly of said cartridge is illustrated in Fig. '1 and willbe further discussed in connection therewith.

Below said supporting member 33 can be seen a partial View of amechanical oscillating mechanism 39. The oscillating mechanism (shown indetail in Fig. 8) imparts an oscillating motion to the support member 36through the agency of va pronged member (see Fig. 8) connected to saidsupporting member and engaging said oscillating mechanism. Theoscillating mechanism is actuated by a gear train comprising a drivengear 55, fastened to .a'shaft 40 which is integral with the oscillatingmechanism 39. Motion is imparted to gear 55 by an intermediate gear 4|which receives its drive from a pinion, illustrated in Fig. 6 as pinion|4I, integral with a hollow shaft, illustrated in Fig. 6 as shaft |40.The pinion extends into a hollow member 42 integral with the framemember 38 and in this position engages the gear 4|. .The hollow shaft|48 is attached to the wheel 29 and is driven thereby as abovedescribed.

When the oscillating mechanism is set in motion,

in 'member 44 and are maintained in this position by an extended portion45A integral with the member 45 and supported within an aperture (notshown), provided for this particular purpose, in the supporting member44. Details of the last-named components are described more thoroughlyin connection with the illustrationin Fig. 10. The position of the'erasing head "43 is such that it follows the course of the recordingmedium without diiculty and has the added advantage that it can beremoved from the supporting member 44 when the device is being used forrecording, thus obviating the possibility of inadvertently erasing anyrecorded material.

In order to ascertain the amount of recording performed, a recordingtime mechanism 52 is provided. Said mechanism is supported between Y Thelength of recording time selected for the particular embodiment is basedon the capacity of the reels 3| Vand 32. It was determined that, for theamount of recording medium present on the reels, a.recording period ofthirty .minutes would be required. Accordingly, a Vdial 58, Fig. 3, wasinput in motion as above described, a pin 53, at-

.tached to .the hub. of the gear 55, engages and attesta drives a gearY513 incorporated lin s'aid timing 'iiiechenisr'n.v Details of theoperation of vsaid timing Amechanism will be discussed below and in'connection with Fig. 13. Avknob 51 serves to preset the amount of time,in minutes, itis desired to record. Said knob is pressed inwardly -and apointer 59 integral with said'knob is rotated tb the desired indicationon the dial 58, Fig. 3. A second pointer 60, below thepointer 59, ispositiiied on said dial so that it coincides with "the 'zero indicationthereon, andin this positionin- 'dicites that a full reel of recordingmedim is available for recording.

Reierring lnow to Fig. 2 there is :illustrated a piuauty or knobs as, saandrei. The knob `la manipulates the means controlling the energize.- tiof lthe'Vrnotor for driving the `recording VAmedium along a pathadjacentfthe head 35 and is vso connected as to coact with the recordingtime mechanism 52 to render the energizing means ine'ectual at theexpiration of the desired recording time. Therefore, let it be assumedthat the timingmmechanism, through the agency of rtheknob 51, is set fora predetermined length f* recording time and the knob I5 is set to the"record position. As the recording time mechanism is actuated, thepointer 66 will commence moving around the inscribed scale 58. 'Whensaid lpointer 60 coincides With the pointer 559I the vknob 51 will Vsnapoutwardlyfand interkfflipt` the motor energizing means.

The interruption of the current to the inotor, by the action of thetiming mechanism, takes place in the following manner. knob 51 is ashaft 6I to which is secured a -gear ,653; Said gear is provided with anaperture, ill'u'strated in Fig. 13 as I9I, in proximity to its outeredge. The pointer 59 fis arranged s'o-that it is in register With theaforesaid aperture. At the other end of the shaft 6I, and integraltherewith, is an annular member 61. This member retains in position aflat metal spring member 68, slotted -atonejeid I90 thereof.y Theslotted end I9I'I of fmember`68 is placed athWart the shaft 6I adjacentthe annular member 61, the other end of Vmember 68 being fastened to ablock of insulating material 69 and to this block is fastened the 'otherend of the Contact I3A.` The reason for this particular arrangement willpresently follow. C'i'd by the Shaft 6I is `a hollow yshaft 64 to "whichattached a gear 65 and Vthe pointer 60. This gear has secured to it apin 66, in register with the -pointer 6U, said pin extending towardthegear- 63. The pin 66 -is so positioned on the gear 65fth`at whenactuated it will be brought Afinto coincidence with the aperture,illustrated in Fig. 13 as I9I, provided in the gear member 63, in

fa manner which will be presently explained.

Assume it is desired to record for a period of minutes. Also assume thatthe pointers 59 and 66 are in the zero position with reference to `thedial 58. In'this position the pin 66 is in coincidence with the apertureand consequently a spring member 19, positioned between the gear 63 andthe wall 1I of the recording time mecha- `nis`m l52, will urge the gear63 toward the gear "65. Since the gear 63 is secured to the shaft 6|,

Connected to the 6 thel gestita., Asa direct resuiuthe nttts 13A and I3B arebrought closer tcgether. It requires; at this4 point, only themanipulation of the knee I5 t the record positin t'o bring the con#tacts ISA and I3B into positive Contact. The knob I5 through the'agencyof 'a cam arrange-'- ment, illustrated in Fig. l1 'as cam, I 86, movesthe contact I3B into Contact with thev ccrit'act I 3A and at the sametime urges the clutch 26 into engagement withthe Wheel 29.

Now as gear 65 rotates, due to the drive parted to it by a driving pin12 which is'tself driven by the` train of gears 55, 4I, etc., the pin 66Will be caused' to come into cincidencewith the aperture in gear 63.lWhen this occurs, lsaid gear 63 will be urged toward the gear 65 yandthe recording will be interrupted 4due to the sepa' aration of thecontacts I3A and I3B. The knob I5 is returned to the ofi position randis now ready to continue recording if desired, 'er te freproduce thealreadyA recorded material.

Hav ng recorded for te "fsu'nied period and it is now desired to listento, or reproduce, 'the recording, the kno-b 51 Yis pushed inwardlyertoward the dial 58 and rotated to zero position, said position being thestarting point of the recording time. The knob I5 is rotated from the oto the rewin position. contacts I3A and I3B together and the sainesequence or' events above described take place with the followingexceptions. The movement of the knob I5 rotates the lshaftlj'l and acam, illustrated in Fig. 11 as a cam IZI, secured to .said shaft I1,causes the clutch 26A to move into engagement with the wheel 28, in amanner to be described below. Motion is consequentiy im` parted to thereel S2 through 'its associated drive ing wheei so and as the medium asis'drawnontt the reel 32 it causes rotation of reel 3| to take place.However, the reel 3| is now caused to rotate in .a Ydirection which isopposite to vits former direction when the device Wa's recording. As aresult the drive to the recording time mech'- anisrn is also reversed.The pointer novv'rotates back toward the zero position on the scale 58and when it arrives at coincidence with the pointer 59, the knob 51again snaps outi'vvardly and interrupts the operation of the device. Theknob I5 is returned to the off position jand the device is prepared forreproduction. For this last-named operation, the knob 50 is rotated "tothe listen position, the knob '59 pushed Airrwardly and set to the tenminute positionv on the scale 58, andthe knob I5again set to the record"position. With the setting of the :knobs asdescribed above, the recordedmaterial will 'be reproduced as will be presently described.

Encompassed within a compartment 46 is an audio amplifier employing aplurality of subminiature radio tubes '151. A pair of contacts "48 isprovided in said amplifier for engaging a`second pair o f contacts(illustrated in Fig. 6) which are a part o-f the cartridge discussed-hereinbe'- fore. The relationship between the two pairs of contactswill be discussed in connection with Fig. 7. Plate current for the radiotubes `111 is provided by a battery $9, and a dry'cell 49A (shown indotted lines) serves 'as the filament supply for said tubes. Bothsources 'of current are easily removed and replaced when necessary. Thestorage cell I2 can be removed with equal facility when it is necessaryto recharge same. H The knob 50, hereinbefore mentioned in connectionwith Fig. l2, controls lthe manipulationmembers.

plished between an input jack v82, through the amplifier to the contacts48 and from said contacts lto the contacts, Iillustrated in Fig. 7 ascontacts |15, connected to the head 35 within the cartridge |59.l In thelsten" position the connections are reversed and the recorded material,induced in the recording medium 53, is conducted from the head 35 viathe conductors, illustrated in Fig. 9 as |10, through the amplier and tothe jack 02 which now serves as an output for the reception of therecorded material. The knob 5| is attached to a Volume control (notshown) provided for in the amplifier and operates Vin a manner familiarto those versed in the art.

Referring now more particularly to Figs. 4 and 5, Fig. 4 is alongitudinal View, in cross-section, of the reel-driving mechanism, andFig. 5 a transverse partial cross-section of said mechanism. The drivenwheel 24 is secured to the shaft 25 and maintained in position by a setscrew 80. A washer 8|, carried by said shaft, and made, preferably, ofbrass, is disposed between the hub of said wheel and a supporting arm 82to reduce the friction therebetween. The supporting arm 82 and itscounterpart 83 serve tosupport the shaft 25, the other ends of saidsupporting arms being carried by a shaft 84, Fig. 5, said shaft being inturn carried by a pair of base members 85 and 05. The supporting arms 82and 83 are integral with an elongated base member 19, Fig. 1, to form asubstantially U-shaped member, the base 19 of the U being carried by theshaft 84. It was necessary to omit the view of the member 19 in Fig. 4to more clear- -ly set forth the clutch-shifting arrangement to bedescribed presently. Adjacent the end of the arm 83, which supportsthe-shaft 25, is an annular member 81. The annular member is secured tosaid shaft by a set screw 88. When the annular member 81 is thussecured, it restricts any possible longitudinal motion of the shaft 81for reasons that will be explained below.

Slidably carried by the shaft 25 is a pair of clutch members 26 and 20A.Both of said members are secured to the shaft 25 by a pair of keys 89and 90, keyways being provided in said shaft and clutch members,respectively, for this to said base members so that said shaft can bemoved longitudinally with ease. The arms 93 and 94 are terminated toform a plurality of open yokes 95 and 90 which engage a pair of annulargrooves 91 and 98 provided for this purpose` adjacent one end lof theclutch members 25 and. 25A. Gear teeth 99 and |00 are provided on theends opposite the grooved ends of said clutch They are radially cut fromthe outer surface of said clutch members to the respective edges ofcircular depressions and |02 provided in each of said clutch members.The lastnamed depressions are provided to allow the free movementtherein of a pair of hollow shafts `|073 and |04 which are carried bythe shaft 25 and secured thereto, respectively, by a pair of pins and|06. A portion of each of said hol- ,low shafts is appreciably smallerin diameter trated, and subsequently the member 8 than those portionswhich are attached to the shaft 25 and form, respectively, a pair ofshoulders |01 and |08, on each of said shafts |03 and A| 04V.` vThereason for this particular construction will be presently described.

Carried by the members |03 and |04 is a second pair of hollow shafts |09and ||0, the inside dimensions of said last-named shafts conformingsubstantially to the outer dimensions of thermembers |03 and |04 andhaving enough clearance therebetween to allow the hollowshafts |09 and||0 to rotate freely upon the members |03 and |04.

The ends of shafts |09 and ||0 which face the gear-cut ends 99 and |00of the clutch members 25 and 26A, are also provided with matchinggear-cut ends and ||2 for engagement with 99 and |00. Opposite the endsand ||2 are flanges ||3 and ||4 integral with each of said shafts |09and ||0, whose circumferences are equal to the larger circumferences ofsaid members |09 and ||0. This arrangement provides a plurality ofgrooves for retaining therein the resilient driving wheels 21 and 28.Disposed between said wheels 21 and 28 is a plurality of bowed disks ||5and H5 which are carried by the hollow shaft member |04 on thediametrically smaller portion thereof.V This last-named portion extendssufficiently beyond the flange ||4 to carry said disks ||5 and H6. Wheneither of the wheels 21 or 28 are put in motion, the disk adjacent willbe caused to rotate with it because the edges of the disks are forcedinto the sides of the wheels 21 and 28. As will be explained further,when one of said wheels rotate, the other is held stationary and becauseof the bowed configuration of said disks, the fact that their concavesurfaces are in intimate contact with each other and that there is asufficient tension between them causes them to have a braking effect onthe wheels 21 and 28. The purpose of this particular arrangement will bepresently explained. The particular concentric arrangement of the hollowshafts |03, |04, |09 and |0 provides means for assembling the wheels 21and 28 with great facility. In practice the wheels 21 and 23 are placedin the grooves provided in the members |09 and ||0. Then the members |03and |04 are inserted within the members |09 and ||0, in the positionillustrated. Now the shaft 25 is inserted in the member |04 and securedto the shaft 25 by the pin |05. Following the latter step, the boweddisks |5 and I5 are placed on the shaft 25, in the position illus- |03is placed on the shaft and secured by the pin |08 to said shaft.

When thus assembled the wheels 21 and 28 rctatefreely on the hollowshafts |03 and |04, said last-named shafts serving to retain the members|09 and |0 in a predetermined position on the shaft 25. The clutchmembers 26 and 20A are then placed on the shaft 25 and `secured to saidshaft by the keys 89 and 90 as movement of the shaft 92 between the basemembers 85and 86. Linear motion is imparted to the "shaft 92 by a cammember |2|, whichis attached to the shaft I1, as shown more clearly inFig. 11, when said shaft is manipulated by the knob I 5.

A yokeflike member |22, positioned .athwart the cams pin |23, is.attached to the shaft 92 by a pin |24V and,` when the shaft |1 iscaused to rotate asrjust described, motion is imparted to theshaft 92.

As illustrated in Fig. 4' the shaft |1 has been `Arotated so that thepin |23 has urged the shaft 92 and its associated components to movetoward the right, Iwith respect to the drawing, and thus causedVthe-clutch 25 to engage the member |09. Since the clutch 26 is keyed tothe shaft'25, rotation of said shaft'will impart motion to the wheel 28.Therefore, the wheel 21 is left free torotateon the hollow shaft |64 andwould ordinarily rotate in the same direction as wheel 28 due tofrictional engagement of the disks v| I5 and- I l' disposed betweenthem. However, since the wheels 21 and 23 are in frictional contact withthe reeledri'ving wheels 29 and 30, as illustrated in Fig. 1, motion isimparted to the wheel 30, the direction of said wheel being such thatthe recording medium 33 is drawn onto the reel 3|. 3|, said mediumcauses the reel l32 and its associated Wheel 29 to rotate. When thusrotated, the wheel 29, which is frictionally engaged with the wheel 21,imparts thereto rotation in a direction opposite to the rotation of thewheel 28.

. y Therefore, the novel arrangement and cooperation of components abovedescribed provide braking means which prevent, under the conditionsrecited above, the continued rotation of reel 32 after reel 3| hasceased to rotate. The braking effect; produced by the coaction of thedisks H5 and |123,v is instantly effective with the cessationof motionof reel 3| and thus prevents `reel 32 from overrunning itself and`piling up the recording medium 33. Furthermore, the recording medium iskept substantially taut.

the 4position where the cams pin 123 is directly under the shaft |1, theclutches v26 Vand 26A will be disengaged from the members |09 and |13.Rotating the shaft |1 to the left, with respect tothe drawing, causesthe clutch `26A to engage themem-ber ||0 and in this position thereel 32will now rotate in the direction-first taken by reel 3| reel 3|, nowhaving imparted to it anopposite rotation, will cause the medi-urn 3.3to :unwind from reel 3| onto reel 32, etc.

It will be evident Vfrom the `aforegoing discussion thatf the membersv|09 and I-I-0 should be `maintained in proper position with-'respect tothenclutch members'Z and 26A. This is accomplished by properly locatingand yfastening As the medium 33 is drawn onto the wheel.

Wheel 24 andannular member 88 to prevent any Referring now to Fig. 6,which illustrates in cross-section the preferred construction lof thereels, the reeladriving means and the supporting means for same, it isdesired to show how this novel construction permits rapid placement ofthe reels 3| and `32 upon their supporting and driving means 29 and 30and the manner in which this assembly is mounted and held to. gether.v

The reels 3| and 32 preferably comprise a pair of disk members |30 and|3|, which may be die cast, machined orpunched and preferably fabricatedor aluminum or similar lightweight ma.- terial, said disks `havingcircular grooves |32 and |33 for supporting a tubular member |34. Inaddition, raised `bosses |35 and 36, concentrica'lly positioned withinthe tubular member |34, and having centrally located apertures, areprovided to receive a second tubular member |31 concentricallypositioned within said member |34. The tubular member |31 supplies addedrigidity to the reels. In addition, .the elongated tubular member |31provides ease of manipulation when assembling. Both reels areconstructed in the -same manner. Therefore, the reference numeralsappliedto the reel 3-2 also apply to the reel 3|. l

The reel-driving wheels 29 and 30 are'b'oth constructed alongpracti-cally'similar lines with one exception, present in the wheel I29.Both wheels have flanges |38 integral with the periphery thereof andraised bosses |39 at the center to provide an aperture for thelinsertion and attachment of a tubular shaft |43. The unattached end ofthe shaft |40 of the wheel 29 has a pinion |4| integral therewith, theteeth of which are cut parallel to the axis of said shaft. In theparticular embodiment, the ypinion 4| was cut in the outer surface ofthe shaft |4il.r The unattached end of the shaft k|42 is untouched. Thelength of the shaft |40 is substantially equal to the llength ofthetubular member |31 plus the length of the pinion I 4I. The shaft 42 vissubstantially equal to the length of the tubular member |31 of the reel3|.

Both of the wheels 29 and'30 have attached thereto pins |43 and |44,respectively.` These pins vare parallel to the axis of, and extend inthe same direction as, the shafts |40 and |42 and are of a diameter andlengthV sufficient to provide a slidable fit when inserted inapertures|45 and |46, provided in the reels 32 and 3|, respectively. When thereels 32 and 3| are slipped onto the shafts |40 and |42, respectively,the pins |43and |44 engage the apertures |45 and |46 and serve to rotatesaid reels when motion is imparted to the wheels v25| a-nd 3&1.

Means for supporting the reels and -wheels lillustrated`-in Fig. 6 areprovided in the form of 'a rod A|41,-having a threaded portioni 48 and aknurlled 'knob |49 at one end thereof. `The threaded portion of said-rodengages -a threaded aperture |50 provided in the hood-like member 42,said member 42 being integral with the .frame member 38,' as moreclearly illustrated in Fig. '7. In practice the reels are slipped ontotheir respective supports, the shafts |40 and |42, and then vpositionedwithin the Vframe member 38, thepinion `|4| extending within Ythe hollowof the member 42. Therod |41 is inserted through the threaded aperture|50, thence through theA hollow shafts |40 and |42 and into an aperture(not shown) provided inthe wall of the frame member 38.` The last-namedaperture is, of course, kin substantial alignment with the threadedaperture |50.Y lWhen the -rod |41 has been inserted to its full "length,the threaded portion |48 Will engage the threaded aperture |56 and, bymanipulating the knob |49 inxthe proper direction, the rod is firmlyheld in place. The length of the rod I41 is such. that the end IIx.isflush with the outer surface of the frame member 38 when said rod iscompletely inserted as above described. The vrecording medium 33 isusually present on one of the reels and, when both reels are inserted inthe'frame member, the recording medium is taken from the loaded reel andplaced in position with respect to the guiding rollers 34A and the head35 as illustrated in Fig. .1 and the free end of the medium secured, bysuitable means, to the unloaded reel. For example, apertures may beprovided in the sides V|36 or I3I of the reels and the free end of themedium secured to the reel by threading said medium through theapertures.

In the particular embodiment of the present invention,preference. hasbeen given to the use of aluminum in the construction of the Wheels 29and,36 and the reels 3| and 32; nevertheless, said components could befabricated of plastic materials, with thevexception of the hollow shafts|46 and I 42. These should be made of a metal suitable for use as abearing surface, it being important that drag, due to friction, be keptdown to a minimum. Needle bearings may be used in the reel and wheelassembly and would further decrease the possibility of reducing unwantedfriction in the rotating members.

Fig. '1 illustrates the cartridge |59 comprising the frame member 38 forsupporting therein, the reel-driving wheels 29 and 36, the reels 3| and32, the supporting member 36 which is in turn slidably carried by therod members 31, only one of said rod members appearing in thisparticular view, and the electro-magnetic head 35 which is supported bythe member 36. Attached to the supporting member 36 is a double-prongedmember |66. As illustrated in Fig. 8, the doublepronged member |66engages a single-pronged member I6 I` which is carried by aduo-directionally-threaded member |62 integral with the shaft 46. Themanner in which the members |66 and I6I cooperate to distribute therecording medium 33 on the reels 3| and 32 was discussed in connectionwith Fig. 1 andthe distributing means were referred to as the reversingmechanism 36. Engagement of the member |66 with the member I5I takesplace when the cartridge |59, above described, is inserted in acompartment |63, Fig. 9, provided for in the case I6.

Attached to the inside of the frame member 38 is a rod |64 which carriesthereon and has attached thereto a member I 65. The member |55 is sofashioned that a portion of it extends beyond a predeterminedcircumference to form a lobe |66 having a pin |61 affixed thereto, saidpin being parallel With the axis of the rod |64. Carried by vsaid rod|64 is a substantially Wedgeshaped member |68, the tapered portion ofwhich is urged into the space |69 between the reel-driving wheels 29 and36 by a helical spring |16. The spring I 16 is carried by the rod |64,one end of said spring being firmly anchored in a boss I'II integralwith .the rod |64. The other end |12 of said spring is positioned behindthe wedgeshaped member |68 and thus exerts the necessary pressure tomaintain the tapered end firmly in place in the space |69.

The aforegoing arrangement provides a novel means for holding thereel-driving wheels 29 and 30 substantially immovable-when the cartridge|59 is removed from the compartment |63. The pin oc i |61 provides meanswhich allow an appreciable amount of rotation of the member |68 withoutinterfering with its ability to maintain the reels immovable. However,when the reels themselves are removed the member |68 will be held in itsposition on the rod |64.

Thus the undesirable results which would follow the removal of thecartridge |59 and subsequent unravelling of the recording mediums whereit is not maintained immovable are simply and emciently taken care of bythe above arrangement.

Fig. 9 taken along line 9-9 of Fig. 1 illustrates clearly the positionof the cartridge |59 when inserted in the case I6. In this position thewedge-shaped member |68 is forced out of the space |69 because the end|13 of the member |68 comes in contact with the unyielding surface of ashelf member |14. The tension on the reeldriving wheels 29 and 36 is nowtransferred from the member |68 and exerted by the wheel 21. Tension onthe wheel 21 is caused by the spring 24A, Fig. l, as previouslydescribed. A space |11 is provided in the frame member 38 to permitcontact of the Vreel-driving wheels 29 and 36 with the wheels 21 and28.-

A pair of contacts |15, insulatingly attached to the frame member 38, isconnected by conductors |16 to the electromagnetic head 35.

v These contacts are urged into intimate contact lwith the contacts 48located in the amplifier section 46 when the cartridge is inserted inthe compartment |63, the insertion of the cartridge likewise causingengagement of the members |66 and IBI as hereinbefore described.

The shelf |14, which is secured within the case I6, supports thereversing mechanism 39. In broken lines are illustrated the train gearcomprising the driving pinion I4I, the intermediate gear 4I, and thedriven gear 55, the last-named gear being attached to the shaft 46, saidshaft being integral with the threaded member I6I. The rotation of thereel-driving wheel 29 through its associated pinion I 4I drives themechanism 39 as previously described.

Fig. 10 is a perspective view of magnetic erasing head 43 and itssupport 44. In this View the solid line illustration depicts the erasinghead 43 held, by its supporting member 45 and its maintaining pin 45A,within the fold of the main supporting structure 44. In the broken lineview it is readily observed that raising the member 45, until it clearsthe back portion 44A of the main support 44, permits the member 45 to beremoved from the aperture engaging the pin 45A. The reasons for thisparticular arrangement were rliescribed hereinbefore in connection withFig.

Another novel feature of the present invention is` illustrated in Figs.11 and 12. It comprises a combination power supply switch I3 and acamactuated arrangement controlled by the shaft I 1. The shaft I1 isrotated by the pair of gears I6, one of which is attached to a shaftISA, said shaft being axed to the knob I5. The other gear is fastened tothe shaft I1 and is actuated by the gear associated with the knob I5.The gears IB are secured to an inner supporting wall |86 in a suitablemanner, said inner wall being a part of the case I 6.

Indents I8I, |82 and |83 are provided in the wall |86 and a springmember |84, attached to the shaft IBA, urges a -pin into said indents tofirmly hold the shaft I1 in the selected posigong2 ("rewindLf"offrecord)illustrated in 13 Manipulation of the knob i rotates the shaft |1, saidshaft simultaneously vcausing a cam mem- .ber |86 and the cam member |2|to respectively urgethe contact 13B toward the contact |3A kand Vtoimpart a linear motion to the shaft 92 through the agency of itsassociated yoke-like member |22 and pin |23 secured to the shaft |1. Theaction. of` the cam |86 is readily evident in theillustration depictedin Fig. 12.

The contacts 3A and |3B of switch I3 are supaway from` |3B. Thevcooperative activity between the recording time mechanism in Fig. 13andthe mechanism described in Figs. 11 and; 12 was de- .ported by ablook|81, saidblock being preferably `fabricated ofinsulating material. Theblock |81 .also serves as a support to carry the shaft I1 at thatendthereof to which is attached the cam |2|. ExtendingV through the block|81 are the terminals |88 and |89 of the contacts |3A and |3B.- To theseterminals are wired thepower supply forthe motor as illustrated inFig. 1. Secured to the contact |3A, at the end oppositethe terminal |88,is the block 69, said block being preferably made of insulatingvmaterial. The block 6911s formed so that it clears theshaft I1.` Tosaid block, on the side opposite to :which is fastened the contact ISA,yis secured a nat spring member 68 terminating in a slotted end |90.This slot is placed athwart the shaft 6| and due to the spring action ofthe member 68 exerts a pressure against the annular .member y61attachedtothe shaft 6|. As previouslydescribed, actuationV of the shaft 6| in alongitudinal direction causes contact ISA to move toward or away fromcontact ISB, said shaft being a part of the recording time mechanism 52,Fig. 13.

Fig. 13 illustrates in greater detail the relation of the gear train inthe recording time mechanism 52. The `gear 65 has imparted to it rotarymotion by the driving pin 12, said driving pin being secured tothe shaft56, said shaft being in turn actuated by the gear 54. The gear 54receives its drive from the gear train 4|, 55, and |4| as illustrated inFig. 9 and previously described. The gear V63 is only rotated by handand is secured to the shaft 6|. Manipulation is by the knob 51,

Fig. 1, attached to said shaft. An aperture |9| is provided .in the gear63and is positioned approximately midway between the periphery of thegear 63 and the shaft 6|. )In addition to being rotated by -hand, theshaft 6| can be moved linearly. Attached4 to the gear 65V, on that sidefacing the gear 63,'i's the pin 66. Said pin extends perpendicularlyfrom the surface of' gear 65 and is secured thereto in exactly the samerelative position as the aperture-j|9| in gear 63.

The present position of the pin 66, as illustrated in Fig. 13, keepsythe gear 63 separated from the gear 65, a distance which is equal to thelength of the pin 66. The length of the pin 66 is determined c bytheamount of clearance desired between contacts |3A and |3B as will bepresently revealed.

i SAssume that the gear 54 has imparted toit a drive in acounter-clockwise direction. This will fresult in the pin 12 driving thegear 65 in a clockimparting a linear motion to the shaft 6|, and Yitsassociated member 61, causev the member 6B to'move to the right, asviewed in the Fig. l2.

This action, of course, causes contact |3A to move scribed in connectionwith Fig. 1.

The components ofthe recording time mechanism 52 are supported betweenWall members 52A and 1 I, said members being held together at apredetermined distance from each other by suitable means not shown inthe drawings. They were intentionally omitted from the drawings to avoidobstructing the more pertinent views..

Attached to the supporting wall member 52A, and not previouslyillustrated, to avoid confusion, is a plurality of flat spring members|92, |93, and |94. Thespring members |92, |93, and |94 are arranged toengage the leading andl following edges of the gears 54, 63, and 65,respectively. The function of said springs isto maintain Asaid gears inproper engagement with respect to each other.

Attention is called to the fact that no particular type of material wasdesignated for many of the components described. It will be obvious tothose skilled in the art that reciprocating .and rotating componentsshouldbe made of, materials suitable for such uses of same. In the caseof rapidly rotating components it may be desirable to substitute rollerbearings for friction-type bearings, etc.

While the present embodiment `described the use of driving means of thefriction type, gear drives fabricated of, proper materials may be usedwith equal facility and low noise level.

Despite the small size of the present invention, it has been constructedto withstand the rough treatment which any portable equipment is usuallysubjected to. Furthermore, the use of a cartridge containing therecording medium .and the recording and reproducing head in properposition with respect to said recording medium, and having extremefacility of loading, isa distinct departure from the previous practiceinthis particular art. This novel arrangement permits the user to carryany number of extra cartridges, previously threaded and ready for use inthe same manner that a photographer carries an extra supply ofphotographic plates.

Theuse of the invention for on the spot recording of important events isbut one of many to which said invention is adapted.

At conferences, its inconspicuous size, portability and absence oftrailing power leads and the necessity of accessible power outletsfor-such leads make the present invention ideal for this type .ofrecording. For the last-named use, it is only necessary to place thedevice 0n the conference table, plug a desk type microphone into thedevice and the invention is ready for instant use.

While there has been described and illustrated a particular embodimentof the present invention, it will be obvious to those skilled in the artthat many changes and modifications may be made Without departing fromthe true spirit and scope vof the present invention.

What is claimed is:v

. 1. A cartridge for use in a unit adapted for magnetic recording andreproduction includingdrivingmeans andsm'eans for producing,mechanically,

voscillatory motiorn comprising: a'frame member; means for supporting anelectromagnetic recording medium within said frame member, saidsupporting means having driving means integral therewith and adapted,upon insertion of said cartridge in said unit, to be driven by saidfirstnamed driving means and in turn to engage and drive said mechanicaloscillation-producing means; i an electromagnetic head supported Withinsaid frame member; means attached to said head for guiding saidrecording medium from one portion of its supporting means along a pathadjacent said head to another portion of said supporting means; and apronged member attached to said head and adapted, upon insertion of saidcartridge in said unit, to engage said oscillatory motion-producingmeans and be driven thereby, said last-named means causing saidrecording medium to be substantially evenly distributed on saidrecording medium supporting means.

2. A unit, adapted for the insertion of a cartridge containing means forsupporting electromagnetic recording media and a combinationelectromagnetic recording and reproducing head and means for guidingsaid media along a path adjacent said head, including: driving mea-ns; adriven member adapted to frictionally engage said driving means; a shaft.attached to said driven member; a second driven member carried by saidshaft and adapted to rotate freely thereon, said second driven memberincluding at least a pair of rotatable members, a pair of substantiallyflat, resilient members disposed between said rotatable members toproduce a braking effect therebetween; a clutch slidably attached tosaid shaft and adapted to be driven thereby, said clutch being disposedon said shaft so as to engage both sides of said second driven member;and means adapted to urge said clutch into alternate engagement withsaid pair of rotatable members, said rotatable members being adapted,upon insertion of said cartridge, to engage. and drive said mediasupporting means within said cartridge.

3.v In combination with an electromagnetic recording and reproducingdevice having means for supporting electromagnetic media and anelectromagnetic head and means for guiding said media alonga pathadjacent said head, including: driving means; a driven member adapted tofrictionally engage said driving means; a shaft attached '.to saiddriven member; a second driven member carried by said shaft and adaptedto rotate freely thereon, said second driven member including at least apair of rotatable members, a pair of substantially flat, resilientmembers-disposed between said rotatable members to produce abrakingeifecttherebetween; a clutch slidably attached to said shaft and adaptedto be driven ithereby, said clutch being disposed -on said shaft soV asto Iengage both sides of said second driven member; and means adapted tourge said clutch into alternate engagement with said pair of rotatablemembers, said rotatable members being adapted to engage and drive saidmedia supporting means.

4. A cartridge for use in a unit `adapted for use in a magneticrecording and reproduction unit comprising: a frame member; means forsupporting an electromagnetic recording medium within said frame member;braking means attached within said frame member and adapted to engagesaid supporting means to maintain said medium supporting meanssubstantially immovable; means for movably supporting an electromagnetichead within said frame member comr prising a plurality of parallel rods;and means Afor guiding said recording medium from o-ne portion o-f itssupporting means along a path adjacent said head to another portion ofsaid supporting means; and means for moving said recording head on saidrods, to uniformly distribute said recording medium on said supportingmeans, said braking means being actuated to engage said supporting meansand said guiding means being deactuated by removaI of said cartridgefrom said unit. l y

5. A unit, adapted for the insertion of a car-V tridge containing a pairof coaxially rotating members for supporting electromagnetic recordingmedia and a combination electromagnetic recording and reproducing head,and means for guiding said media along Ya path adjacent said head,including: driving means; a source of .current for energizing saiddriving means; a driven member adapted to frictionally engage saiddriving means; a shaft attached to said driven member; a clutch slidablyattached to said shaft and adapted to be driven thereby; a second drivenmember carried by said shaft and adapted to rotate'freely thereon; meansadapted to urge said clutch into engagement with said second ,drivenmember, said second driven member being adapted, upon the insertionofsaid cartridge; to drive one of said media supporting members; andcontrolling means including a switch for controlling said current anddisengaging said clutch, whereby said media supporting means and powerare simultaneously controlled.

6. An electromagnetic recording and reproducing device comprising: apair of coaxially rotating members for supporting electromagnetic media;an electromagnetic head; means for guiding said media along a pathadjacent said head; driving means; a source of current for energizingsaid driving means; a driven member adapted to frictionally engage saiddriving means; a shaft attached to said driven member; a clutch slidablyattached to said shaft and adapted to be driven thereby; a pair ofdriven members carried by said shaft and adapted to rotate freelythereon; and selective means adapted to urge said clutch into engagementwith either of said driven members, each of said driven members beingadapted to drive one of said media supporting members.

ROBERT GRAY. ROBERT ELLIS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1, 123, 147 Sherman Dec. 29, 19141, 237, 496 Fankhauser Aug. 21, 1917 2, 005, 596 Scheibell June 18, 19352, 213, 631 Heuer 1 sept'. 3, 1940 2, 321, 812 Heller June 15, 1943 2,364, 556 Somers Dec. 5, 1944 2, 419, 476 Begun Apr. 22, 1947 FOREIGNPATENTS Number Country Date 297,327 Great Britain Dec. 17, 1929 363,751Germany Nov. 13, L1922 375,749 Germany May 18, 1923

